Commercial applications for soy isoflavones have grown significantly in recent years. Isoflavones are used in health foods and as nutritional supplements. More recently they are being investigated as antioxidants, protecting skin from UV damage when taken orally or used topically. More importantly, isoflavones and their derivatives have potential to be used as pharmaceuticals in the fight against certain cancers, heart disease, and osteoporosis. Fermalogic identified a method for the isolation of isoflavones as a by-product of the Saccharopolyspora erythraea erythromycin fermentation, but in order to be commercially successful, a problem with degradation of the isoflavones during the fermentation had to be solved. In Phase I of this project the first metabolite of the isoflavone degradation pathway was identified. During Phase II we hope to find the gene responsible for this degradation and inactivate it. This should raise production levels of isoflavones to commercially useful levels. In addition/other bacterial fermentations will be investigated for the production of new biologically active isoflavone metabolites.